1. Field of the Invention
The present invention relates generally to content providing services, and more particularly, to the selection of a Content Delivery Network (CDN) based on user location.
2. Description of the Related Art
As Internet Protocol (IP)-based communication services and IP-based broadcast services converge, opportunities are emerging for the development of new business models and services in the industry. An example of a technology that clearly illustrates this convergence is IP Television (TV) technology, which provides conventional TV, voice and information services. Specifically, IPTV technology provides flexible communication and broadcast services to fixed terminals, such as set-top boxes, Personal Computers (PCs) and TV sets, as well as to mobile devices, such as mobile phones, Personal Digital Assistants (PDAs) and laptop computers. The flexible communication and broadcast services may be provided in any environment using wired, wireless and broadcast networks.
IPTV services may be classified into an Open Internet model or an IP Multimedia Subsystem (IMS)-based Managed model. In an IMS-based Managed model, a Call/Session Control Function (CSCF) server selects an appropriate application server in response to a user's service request message based on user information. The service request message is then forwarded to the selected application server.
Referring initially to FIG. 1, a diagram illustrates a network for providing an IMS-based IPTV service. A user 102 (also referred to as a User Equipment (UE) or a User Agent (UA)) sends a service request message to an IPTV controller 104. Specifically, in the IMS-based IPTV service, the service request message is a Content on Demand (CoD) service request message. The IPTV controller 104 retrieves user profile information corresponding to the user 102 from a server 106 that manages user profiles. The IPTV controller 104 performs an authentication process for the user and the requested service based on the retrieved user profile information. If the user 102 and the requested service are successfully authenticated, the IPTV controller 104 selects a Media Control Function (MCF) module 110 and a corresponding CDN 108 from a plurality of CDNs (CDN1, CDN2, CDN3) based on predetermined criteria in the user profile information. The IPTV controller 104 forwards the service request message to the selected MCF module 110.
Typically, a default CDN to be utilized in delivery of a service to the user is defined when the user registers with the IMS network, and is stored in the user profile information. Thus, the service request message is forwarded to the default CDN stored in the user profile information absent any specific user request to the contrary.
The MCF module 110 selects a Media Delivery Function (MDF) module 112 having the content requested by the user 102 in the CoD service request message, from a plurality of MDF modules (MDF1, MDF2) in the CDN 108. The MDF module 112 functions as a server that delivers the content to the user. The MCF module 110 may utilize various selection criteria in selecting the MDF module 112. For example, the MDF module 112 may be selected in accordance with at least one of a policy of the service provider, a general traffic load, and a user location. The selection of the MDF module 112 based on user location can be implemented as set forth by the service provider. After the MCF module 110 selects the MDF module 112, a connection between the user 102 and the MDF module 112 is established in order to provide the user 102 with a transmission, such as, for example, a CoD transmission.
In order to guarantee high service quality for a CoD service, CoD content that is within a predetermined range of jitter is continuously transmitted to the user 102. As the distance between the MDF module 112 and the user 102 increases, the routing path becomes more complicated. Complicated routing paths cause congestion and an increase in jitter, resulting in a degradation of service quality. The use of user location as a criterion in MDF module selection attempts to minimize the transmission distance to the user 102.
A conventional MCF module selects an MDF module closest to a user from among the MDF modules under the control of the MCF module. However, because the MDF module is selected based on location information preset by the service provider, conventional MDF module selection does not take into account the mobility of the user and cannot guarantee that the selected MDF module is the MDF module in the CDN that is closest to a current location of the user. Further, the selection of the MCF module and corresponding CDN does not consider user location information. Thus, it is possible that an MDF module of another CDN is actually closest to the current location of the user.